Allow user to provide levels, or levels plus ordering (no ranking or crossing minimization), and let dot finish

This issues is migrated from the wishlist HTML page at https://graphviz.org/doc/todo.html.

Git blame shows this is from 2014:

1c6c6bb492 (Emden R. Gansner 2014-05-15 10:12:04 -0400  59) Allow user to provide levels, or levels plus ordering (no ranking or crossing minimization), and let dot finish

This one is a bit unclear to me:

• "let dot finish" what?
• Is this like https://stackoverflow.com/questions/25734244/how-do-i-place-nodes-on-the-same-level-in-dot ?